#region Id property

    /// <summary>Gets or sets the Id. </summary>
    [Bindable(true, BindingDirection.TwoWay)]
    [Editable(true)]
    [Display(Name="Id", AutoGenerateField=true)]
    [IbVal.RequiredValueVerifier( ErrorMessageResourceName="Customer_Id")]
    [DataMember]
    public int Id {
      get { return PropertyMetadata.Id.GetValue(this); }
      set { PropertyMetadata.Id.SetValue(this, value); }
    }
    #endregion Id property

    #region Name property

    /// <summary>Gets or sets the Name. </summary>
    [Bindable(true, BindingDirection.TwoWay)]
    [Editable(true)]
    [Display(Name="Name", AutoGenerateField=true)]
    [IbVal.RequiredValueVerifier( ErrorMessageResourceName="Customer_Name")]
    [DataMember]
    public string Name {
      get { return PropertyMetadata.Name.GetValue(this); }
      set { PropertyMetadata.Name.SetValue(this, value); }
    }
    #endregion Name property
    #endregion Properties

    #region Navigation properties

    #region Language property

    /// <summary>Gets or sets the Language. </summary>
    [Bindable(false)]
    [Display(Name="Language", AutoGenerateField=false)]
    [DataMember]
    [IbEm.RelationProperty("LanguageCustomer", IbEm.QueryDirection.ToRole1)]
    public Language Language {
      get { return PropertyMetadata.Language.GetValue(this); }
      set { PropertyMetadata.Language.SetValue(this, value); }
    }
    #endregion Language property
    #endregion Navigation properties

I created a new test app

in the edmx i created two entities "Customer" and "Language" adding an association between the two so Customer has a language and Language has Customers

then I generated the sql to create the database

-- --------------------------------------------------
-- Entity Designer DDL Script for SQL Server 2005, 2008, and Azure
-- --------------------------------------------------
-- Date Created: 09/17/2010 19:39:39
-- Generated from EDMX file: c:\users\koen.skn\documents\visual studio 2010\Projects\WindowsFormsApplication1\ClassLibrary1\Model1.edmx
-- --------------------------------------------------
SET QUOTED_IDENTIFIER OFF;
GO
USE [test];
GO
IF SCHEMA_ID(N'dbo') IS NULL EXECUTE(N'CREATE SCHEMA [dbo]');
GO
-- --------------------------------------------------
-- Dropping existing FOREIGN KEY constraints
-- --------------------------------------------------
IF OBJECT_ID(N'[dbo].[FK_LanguageCustomer]', 'F') IS NOT NULL
    ALTER TABLE [dbo].[Customers] DROP CONSTRAINT [FK_LanguageCustomer];
GO
-- --------------------------------------------------
-- Dropping existing tables
-- --------------------------------------------------
IF OBJECT_ID(N'[dbo].[Customers]', 'U') IS NOT NULL
    DROP TABLE [dbo].[Customers];
GO
IF OBJECT_ID(N'[dbo].[Languages]', 'U') IS NOT NULL
    DROP TABLE [dbo].[Languages];
GO
-- --------------------------------------------------
-- Creating all tables
-- --------------------------------------------------
-- Creating table 'Customers'
CREATE TABLE [dbo].[Customers] (
    [Id] int IDENTITY(1,1) NOT NULL,
    [Name] nvarchar(max)  NOT NULL,
    [Language_Id] int  NOT NULL
);
GO
-- Creating table 'Languages'
CREATE TABLE [dbo].[Languages] (
    [Id] int IDENTITY(1,1) NOT NULL,
    [Name] nvarchar(max)  NOT NULL
);
GO
-- --------------------------------------------------
-- Creating all PRIMARY KEY constraints
-- --------------------------------------------------
-- Creating primary key on [Id] in table 'Customers'
ALTER TABLE [dbo].[Customers]
ADD CONSTRAINT [PK_Customers]
    PRIMARY KEY CLUSTERED ([Id] ASC);
GO
-- Creating primary key on [Id] in table 'Languages'
ALTER TABLE [dbo].[Languages]
ADD CONSTRAINT [PK_Languages]
    PRIMARY KEY CLUSTERED ([Id] ASC);
GO
-- --------------------------------------------------
-- Creating all FOREIGN KEY constraints
-- --------------------------------------------------
-- Creating foreign key on [Language_Id] in table 'Customers'
ALTER TABLE [dbo].[Customers]
ADD CONSTRAINT [FK_LanguageCustomer]
    FOREIGN KEY ([Language_Id])
    REFERENCES [dbo].[Languages]
        ([Id])
    ON DELETE NO ACTION ON UPDATE NO ACTION;
-- Creating non-clustered index for FOREIGN KEY 'FK_LanguageCustomer'
CREATE INDEX [IX_FK_LanguageCustomer]
ON [dbo].[Customers]
    ([Language_Id]);
GO
-- --------------------------------------------------
-- Script has ended
-- --------------------------------------------------

In my app I do this

using System;
using System.Windows.Forms;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        ClassLibrary1.Model1Container manager =
            ClassLibrary1.Model1Container.DefaultManager;
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            ClassLibrary1.Language lang = new ClassLibrary1.Language();
            lang.Name = "Dutch";
            lang.EntityAspect.AddToManager();
            ClassLibrary1.Customer customer = new ClassLibrary1.Customer();
            customer.Name = "Koen";
            customer.Language = lang;
            customer.EntityAspect.AddToManager();
            manager.SaveChanges();
        }
        private void button2_Click(object sender, EventArgs e)
        {
            foreach (var item in manager.Customers)
            {
                MessageBox.Show(item.Language.Name);
            }
        }
    }
}

I click button 1 and then button 2 and i get a messagebox showing my language name

i close the app and then the debugger stops at the Langiage getter in the Customer:

 #region Language property

    /// <summary>Gets or sets the Language. </summary>
    [Bindable(false)]
    [Display(Name="Language", AutoGenerateField=false)]
    [DataMember]
    [IbEm.RelationProperty("LanguageCustomer", IbEm.QueryDirection.ToRole2)]
    public Language Language {
      get { return PropertyMetadata.Language.GetValue(this); }
      set { PropertyMetadata.Language.SetValue(this, value); }
    }
    #endregion Language property
    #endregion Navigation properties

giving this error : Index was outside the bounds of the array.

Can someone please help us out here, thx